Kirk and Spock beam down to the surface of planet Organia to negotiate for the erection of a Federation base on that planet. Hostilities between the nearby Klingon Empire and Federation have reached alarming heights and it is feared that the medieval culture of the Organians will not be able to withstand a Klingon attack. However, the Organian Council, comprised of five seemingly pleasant, benign elderly men, insist that they prefer to stay with their more primitive culture.

When Kor and his Klingon force attack the planet, Kirk and Spock go undercover as Organian and Vulcan traders. They are captured by the Klingons, and to their surprise, the Organians free them with ease. In turn, the Klingon ship and the U.S.S. Enterprise square off to battle in orbit of the planet.

Displeased by the outbreak of violence, the Organians reveal themselves to be powerful creatures of pure energy who easily neutralize the weapons on both ships, thus ending the threat for the moment.

Back on the U.S.S. Enterprise, Kirk feels certain that the Organians will not only take care of themselves in the future, but monitor their surroundings for any hint of hostilities.